Digital mental health intervention for reducing symptoms of insomnia, depression, anxiety, and stress among Hong Kong COVID-19 survivors

Abstract

Introduction

Emerging evidence links COVID infection with mood disturbances and sleep problems, including insomnia, depression, anxiety, and stress, sometimes persisting beyond the acute phase (long COVID). This study aims to evaluate the effects of digital mental health intervention for these symptoms between post-COVID individuals and non-COVID controls in Hong Kong.

Method

In this pre–post intervention study with 12-month follow-up, 146 participants with DSM-5 insomnia disorder, including COVID-survivors (n = 69) and non-infected controls (n = 77), completed an app-based cognitive behavioral therapy for insomnia (CBT-I). Changes in Insomnia Severity Index (ISI), Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder Questionnaire-7 (GAD-7), and Perceived Stress Scale-10 (PSS-10) were analyzed using linear mixed models adjusted for age and sex. Time × Group interaction terms tested whether COVID status moderated intervention effects. Post-hoc analysis calculated the between-group differences in mean changes from baseline with a 95% confidence interval (CI).

Result

COVID infection significantly moderated changes in stress (time × COVID: p = 0.04) and marginally moderated insomnia severity improvement (time × COVID: p = 0.05). COVID survivors showed greater ISI reduction than controls at post-intervention (estimated mean difference [95%CI]: -1.68 [-3.29,-0.07], p = 0.04), with similar sustained improvements through 12 months. However, COVID survivors exhibited less stress improvement at 6-month follow-up (1.95 [0.20,3.70], p = 0.03). Improvements in depressive and anxiety symptoms were similar between groups (p for interaction > 0.05), with significantly improved depressive and anxiety symptoms at post-intervention (PHQ-9: -2.69 [-3.54,-1.84], p < 0.001; GAD-7: -1.71 [-2.49,-0.94], p < 0.001) which sustained up to 12 months.

Conclusion

Digital CBT-I effectively improved insomnia, depression, and anxiety in both COVID survivors and controls over 12 months. COVID infection history modestly altered trajectories of stress, with attenuated PSS-10 reduction at 6 months in COVID survivors, suggesting the need for tailored stress-management strategies in post-COVID care.